Positive Electrode Performance of Nonflammable Lithium Secondary Battery with Ambient-Temperature Molten Salt Electrolyte

Abstract

The positive electrode performance of the LiCoO₂ electrode in the LiCl saturated AlCl₃-1-ethyl-3-methylimizadolium chloride (EMIC) + SOCl₂ melt as the electrolyte for nonflammable lithium secondary batteries was evaluated. In the cyclic voltammogram of the LiCoO₂ electrode in the melt, the oxidation and reduction waves corresponding to the electrochemical intercalation / deintercalation reactions of Li⁺ were observed at 3.5~4.2 V vs. Li⁺/Li, and it suggested that the LiCoO₂ electrode operated well in this melt. From charge and discharge evaluations, it was known that the discharge capacity was about 130 mAh g^-1 and the coulomb efficiency was maintained of more than 93% during ten cycles. It became clear that the LiCoO₂ electrode operates quite as a positive electrode in the melt.